1. Field of the Invention
The present invention is directed to new and improved feeders for welding, cladding, overlaying and the like, and particularly apparatus wherein powdered alloy materials and an electrode wire for producing an alloy weld are fed and deposited in desired amounts on the area to be fusion welded or weld overlayed and the like which provides an alloy weld of a predetermined composition.
2. Description of the Prior Art
Due to the difficulty of providing homogeneous mixtures to the weld zone, a major problem in fusion welding or weld overlaying is the provision of alloy welds of uniform composition or analysis. For example, premixing of metals does not provide homogeneous mixtures to the work because the heavier metal particles settle out, the larger particles rise to the surface and the more angular particles rise to the top in storage, transportation or other movement. The same problem exists in premixing flux material with alloy metal or metals.
The provision of a feeder which feeds homogeneous mixtures of metal alloy materials to the work and by which a fusion weld or weld overlay is obtained of uniform composition or analysis and either in open arc, series arc, submerged or shielded welding has been highly desirable. It would also be desirable to simultaneously feed materials in desired amounts with the electrode so that accurate, predetermined, homogeneous mixtures and welds are obtained without any special or expensive processing or premixing of the various metals. It would be desirable to provide a feeder capable of feeding a variety of materials, even non-compatible materials, to the weld zone simultaneously, the driving means for the feeding of each such material being independent of the driving means for the feeding of the other materials and independently of the driving means for the electrode wire. Also, it would be very desirable to provide a feeder capable of changing the amounts of materials or ratios of the materials without having to stop the feeder and adjust or change parts.
My prior U.S. Pat. No. 3,172,991 is the closest art of which I am aware. It discloses a feeder for welds which utilizes a plurality of material feed wheels. All the wheels are mounted to connecting shafts which act as a unit and are driven by the electrode wire as the wire is fed through the machine. The speed of the wheels is a slave to and limited by the speed of the wire and, relatively speaking, there can be very little adjustment in the wire speed. This, in turn, severely limits the freedom of adjustment of the amounts of materials deposited in the weld zone. Also, the size of the feed wheel pockets severely limits the range of deposition rates. In order to significantly change deposition rate, the apparatus must be stopped, the old feed wheel removed, and a new feed wheel with different characteristics installed. This is a tedious and inefficient welding method.